Integrated voltage testing systems for low voltage applications

The Wega model for low-voltage applications, based on IEC 62271-213, ensures maximum operational safety.

Is the installation live or dead? This question is fundamental, and a precise answer is essential when service or maintenance personnel are working on switchgear and cables. This also applies to switchgear with rated voltages up to 1 kV. However, IEC 62271-213 only applies to systems with rated voltages above 1 kV. Users of low-voltage switchgear, e.g. in the paper industry, who usually operate with three-phase networks and systems with rated voltages between 400 and 700 V, have expressed the wish to apply the proven safety concepts of high voltage to low voltage as well. In industrial plants in particular, where several switchgears are located next to each other, it is essential for personal safety that the operating personnel can see whether a switchgear is live or dead before opening it. 

In high and medium voltage systems, e.g. at voltage levels of 10 kV or 20 kV, capacitive decouplers are usually present in the switchgear, where integrated voltage detecting systems in accordance with IEC 62271-213 are already successfully used and thus increase the safety of the grid personnel. Such capacitive couplers are not present in low-voltage switchgear.

However, in order to apply the safety concepts of IEC 62271-213 in low-voltage systems, Horstmann has developed a low-voltage interface box that fulfils this function. The three phases of a low-voltage network are connected to the interface box and connected to the Wega 1 LV display unit via a connecting cable. The interface box takes care of the capacitive coupling and the Wega 1 LV processes the signals and displays the voltage state.

The latest Wega 1 LV model now enables voltage testing based on IEC 62271-213. The proven safety concepts from medium and high voltage are now possible for low voltage applications.

The Wega 1 LV deviates from IEC 62271-213 in two respects:

1. The standard was actually developed for rated voltages > 1 kV, but the safety concepts are also used for low voltage in Wega 1 LV.

2. The voltage arrow symbol for "voltage present" is already displayed at a voltage of 50 V to warn the user of dangerous residual voltages. The dot symbol in the display, which in the Wega series indicates that the interface conditions according to IEC 62271-213 are fulfilled, is also designed for the Wega 1 LV according to the thresholds of IEC 62271-213.

The Wega 1 LV is designed such that when the switchgear operates from 400 V to 700 V, the interface conditions are also met at the LRM sockets in accordance with IEC 62271-213. This makes it possible to use phase comparisons with phase comparators in accordance with IEC 62271-215 or IEC 61243-5 (e.g. Horstmann Orion 3.1/ M1) in the low-voltage range.

Horstmann produces high-quality products that are second to none. Everything starts with the development and design at our plant in Heiligenhaus. From the printed circuit board to the housing to the encapsulation, we focus on quality and precision "Made in Germany". Our customers benefit not only from outstanding German craftsmanship, but also from an efficient supply chain. The usual delivery time is only 2-3 weeks. Thanks to our good stock levels and flexible production, partial deliveries of larger quantities are also possible at short notice. This flexibility is one of our strengths and contributes to our well-known reliability.

You can find further information here.